The emergence of cloud computing services has made data more scalable, flexible and convenient for organizations and individual users. Yet, it profoundly impacts digital forensic investigation, introducing diverse challenges. Unlike traditional forensics, where the evidence can easily be extracted from local storage, the cloud forensic investigators face complexities such as remote servers, distributed data, multi-tenancy, encryption and issues related to jurisdiction. This blog provides insights on how cloud services impact the digital forensics domain and suggests remedies for the digital forensics industry to keep up with the evolving nature of cloud services.

Some of the key impacts that cloud services have on digital forensic investigations are as follows:

• Data distribution and complexity: Cloud environments are naturally distributed, with data and services hosted on vast arrays of remote systems in many locations. This exponentially complicates the investigator's job of identifying and tracking all relevant pieces of evidence. Data in the cloud is frequently fragmented and stored in various formats depending on the Cloud Service Provider (CSP) and the services utilized (such as IaaS, PaaS, SaaS), complicating any forensic investigator's attempt to obtain an overall picture.
• Limited access and physical control: In most scenarios, forensic investigators do not have direct physical access to the underlying hardware and infrastructure in the cloud. The lack of direct access to data and the hardware often causes forensic investigators to become solely reliant on the services provided by the CSP, which introduces some dependencies and delays in the investigation. The cloud data retention policy, infrastructure and security measures are also under the control of the CSP, which limits the investigator's options and impacts the availability and integrity of digital evidence.
• Data volatility and ephemerality: Data stored in the cloud can be highly volatile, subject to changes or destruction based on CSP policies, user actions or automated processes. Because of this volatility, it is necessary to retrieve and collect salient aspects of that data quickly. Some ephemeral resources, e.g., temporary VMs or containers, may be available for very short times. Therefore, rapid live forensics techniques and data collection are required on priority, which may not always be possible.
• Legal issues: The cross-jurisdictional nature of the cloud means that data could reside in geographically diverse locations, each having its own set of laws, privacy, law enforcement clauses and requirements. This raises significant legal issues during an investigation. Obtaining legal authority to gain access to data bound by a foreign jurisdiction is usually a lengthy legal process, sometimes requiring international collaboration of specific designated individuals and agencies. Further complicating matters, there are many regulatory statutes, such as the Electronic Communications Privacy Act (ECPA), Stored Communications Act (SCA), General Data Protection Regulation (GDPR) and other data privacy laws, which may, in some cases, prevent or curtail access to certain types of data.
• Multi-tenancy and shared environment: Most cloud providers use a multi-tenancy approach where many users work on the same infrastructure and share physical resources. This setup creates challenges for forensic investigations with the inability to directly access the required data hosted on the shared infrastructure without prior authorizations and permissions, as it may violate the privacy of other tenants. The default multi-tenant characteristic of most cloud environments creates special considerations for isolation and handling of data during an investigation.
• Data encryption and security features: Increased use of encryption by CSPs to protect confidentiality may thwart forensic investigations, as the investigator may be unable to decrypt the data. The inherent security features of the cloud environment, although required for protection, make it more difficult for an investigator to review and obtain data, limiting their ability to review data and increasing their reliance on the CSP independently. Decrypting the data without authorization and cooperation from the provider can be almost impossible.
• Chain of custody challenges: While a strict chain of custody can be maintained in traditional forensic cases where the device is in the investigator's physical control, this is not true in cloud forensic cases. Establishing a chain of custody can become difficult with evidence stored somewhere else, on a cloud server or a third-party service provider. The forensic investigators depend on external third parties for evidence collection and preservation, which may not be fully verifiable and consequently may not be legally admissible in the court of law.
• Emerging services and changing cloud architecture: Constantly emerging technologies and services related to the cloud make the task of forensic investigators more challenging. To accurately analyze and draw valuable insights from data produced from newly emerging cloud platforms and service models, investigators need to keep updating their knowledge, skills and tools. Also, due to the constantly evolving nature of cloud services, cloud forensic methodologies lack a universally standardized approach in contrast to traditional forensics, which means investigators cannot depend on a standard set of protocols and procedures. The lack of a formalized, standard set of practices often leads to challenges concerning the admissibility of evidence in the court.

Following are some suggested remedies to address these challenges:

1. Work on cloud-specific forensic tools and methods: Design and develop automated forensic tools that can interact with cloud APIs to extract forensically viable data from multiple CSPs (AWS, Azure, GCP etc.). Improve information collected from virtualized machines, containers and serverless systems in the cloud. Refine cloud-native logs, such as audit, access, activity monitoring logs etc., to reconstruct events for malicious activity detection. 
2. Develop legal frameworks and promote international cooperation: Focus on the global unification of laws and policies on digital evidence stored in the cloud and cross-border access to data. Enhance collaboration between law enforcement and CSPs to improve the efficiency of the data request process and timely access to evidence while protecting legal and privacy rights. 
3. Alignment with cloud service providers: Effective lines of communication and protocols should be established between forensic investigators and CSPs to facilitate streamlined evidence preservation, collection and disclosure processes. Encourage CSPs to openly provide information related to the locations where data is stored and the policies regarding retention and security of the data. 
4. Emphasizing forensic readiness in the cloud: Require organizations to take proactive steps to aid future forensic investigations in cloud environments, like extensive logging, good data-retention processes and well-defined secure configuration implementation. Develop Cloud Forensics as a Service (CFaaS), which consists of cloud-tailored incident response procedures that detail cloud forensics data gathering, retention and investigation strategies. 
5. Using automation and AI: Deploy AI and ML to automate cloud data analysis, anomaly detection and incident detection. Automated solutions for managing evidence collection and processing in cloud environments will allow investigators to work much more efficiently and resolve cases quickly. 
6. Standard practices for cloud forensic investigations: Industry-wide practices and standards for conducting forensic investigations in the cloud must be developed. This will ensure consensus on the collected evidence's consistency, reliability and validity. 
7. Training and education for forensics professionals and experts: There is an urgent need to upskill with training and education focusing on the unique challenges and techniques of conducting investigations in cloud environments. Specialized certifications and skill sets must be devised for investigators conducting investigations in cloud environments.

Cloud computing is challenging traditional ways of working in many industries and work areas—digital forensics is just one of them. Addressing these challenges with a blend of innovative technology, legal reforms, improved cooperation and better planning can help the digital forensics field adapt to cloud computing while continuing to aid investigations in a world where cloud computing is the norm.